December 01, 2004

Marijuana and Psychosis Link

Yet another research study suggests that Frequent cannabis use during adolescence and young adulthood raises the risk of psychotic symptoms later in life, research suggests.

The risk was much higher in young people who were already genetically vulnerable to developing psychosis

It is thought cannabis disrupts the balance of the key mood chemical dopamine in the brain.

The research, by Maastricht University, is published by the British Medical Journal.

Lead researcher Professor Jim van Os told the BBC News website that using cannabis was not a good idea for these people.

The risk appears greatest for those with a predisposition to psychosis, as evidenced by mild signs of psychosis at the outset of the study. Within this group - about one-tenth of the total - 51% of users experienced symptoms compared with 26% of non-users.

He said: "If there is a family or personal history of mental frailty - stay away form it!"

Martin Barnes, chief executive of the charity DrugScope, said: "The research underlines that there are potentially serious health risks associated with cannabis use, particularly for young people.

"The challenge is to ensure that messages on cannabis use are understood by teachers and health professionals working with young people and conveyed in ways that young people will listen to.

"Shock tactics alone rarely work, but we need to get across that just because you know people who appear to be OK using cannabis, it doesn't mean that are or that it will be OK for you.

Robin Murray of the Institute of Psychiatry in London, UK, notes that cannabis smoking accounts for about 8% of serious cases of psychosis (including schizophrenia).